Kleinite Locality: McDermitt Mine (Cordero Mine; Old Cordero Mine), Opalite District, Humboldt County, Nevada , USA ( Locality at mindat.org ) Size: small cabinet, 9.8 x 6.4 x 3.8 cm Kleinite A particularly rich specimen with a large display face and sharp crystals to 1mm. Excellent orange color! Excellent discrete crystals. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Kleinite
A rare mercury ammonium chloride found only in mercury deposits of the US and Germany, alongside calcite and gypsum.
Intro adapted from Wikipedia (CC BY-SA).
Kleinite is an IMA-recognized mineral species in the sulfate class, with the chemical formula (Hg₂N)(Cl,SO₄)·nH₂O.
It crystallizes in the monoclinic crystal system.
Key properties: Mohs hardness 3.5–4; specific gravity 7.9–8; Sulfur-yellow streak; Adamantine to greasy luster; optically biaxial.
IMA symbol Kle, grandfathered status — known before the IMA’s founding, named in 1905.
Found in hydrothermal mercury deposits.
It is found associated with Terlinguaite, gypsum, barite, calcite, other mercury minerals (Terlingua, Texas, USA); mosesite, calomel, montroydite (McDermitt mine, Nevada, USA).
The mineral was named to honor Carl Klein (1842–1907), Professor of Mineralogy, University of Berlin, Berlin, Germany.